Paper-cutting machine



(No Model:) v

R. D.-ORAWPORD. PAPER CUTTING MACHINE.

Patented Sept, 6, 1892'.

B Y W I 0., unu-rmumo wumuarou, o. c.

UNITED STATES PATENT OFFICE.

ROBERT D. CRAWFORD, OF EAST PEPPERELL, MASSACHUSETTS.

PAPER-CUTTING MACHINE.

SPECIFICATION forming part of Letters Patent No. 482,228, dated September 6, 1892. Application filed September 18,1891. Serial No. 406,068. (No model.)

To all whom, it may concern.-

Be it known that I, ROBERT D. CRAWFORD, of East Pepperell, in the county of Middlesex, State of Massachusetts, have invented certain new and useful Improvements in Paper-Cutting Machines, of which the following is a description sufficiently full, clear, and exact to enable any person skilled in the art or science to which said invention appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is an elevation of a portion of a paper-cutting machine, showing my improvement in use; Fig. 2, an edge elevation of a pile of paper arranged in position for cutting; Figs. 3 and 4, vertical transverse sections of a portion of the bed of a paper-cutting machine, showing details of construction in my improvement; and Fig. 5, a sectional elevation illustrating modification.

Like letters of reference indicate corresponding parts in the difierent figures of the drawings.

In finishing card-board and similar stiff pa per it is customary to interpose zinc or copper plates between the sheets, which are then run between press-rolls under great tension or submitted to pressure in a screw or cam press. This solidifies the body of the sheet, as well as imparting a finish or calender. The compression is so great the edges or portions of the sheets projecting beyond the metallic plates are left appreciably thicker than the body of the sheet. These edges are trimmed by the cutting-machine to reduce the sheets to the proper dimensions. As such machines are of ordinary construction, it is not deemed essential to herein particularly illustrate or describe the same.

The pile A of card-board, arranged as described, is disposed on the bed B of the cutting-machine, the thickened end Z) projecting over the edges of said bed the length it is desired to trim therefrom, the knife D, passing vertically by the edge of the bed,cutting said edges. To cut the whole of said thickened portions away would ordinarily waste too much stock. The inner ends of said portions, therefore, rest on the bed, and when the press 0 is forced against the pile its pressure is less on the body of the sheets than at the edges.

The knife, passing closely to the edge of the bed, tends to draw succeeding sheets toward it as it passes through the pile, the press not bearing sufficiently hard against the body of the sheets to hold them. Some of the upper sheets are thus frequently cut of too small a size.

My invention is designed especially to overcome this objection, and in carrying it out I make use of means which will be readily understood from the following explanation:

To the cutting-edge of the bed I attach a depressibleprojection,whichisnormallyflush with the face of the bed. This projection I preferably construct of a hinged bar H, which is triangular in cross-section. Any number of hinges d may be employed in securing the bar H to the edge of the bed B. A coiled springf is interposed between the edge of the bed and the adjacent edge of the bar I-I, said spring acting expansively to hold a face g of said bar in the same horizontal plane as that of the face of the bed 13.

The knife Dis disposed so that in cutting it will pass by the cornert'of the bar, asshown in Fig. 1. The pile of card-board A being arranged on the bed, the thickened ends 1) project over the spring-pushed bar, as shown,

a portion of said ends resting on said bar. When the press (J is forced onto the pile A, said ends I) are bent or curved slightly downward, the bar II giving sufficiently to permit this. This permits the press to engage with equal force the whole surface of the sheets, holding the pile rigidly against the bed and preventing the sheets from drawing as the knife passes through them. The width of the bar is intended to be such that the point mof the card-board at which the thickened portions 1) commences shall register with the main edgep of the bed B. The knife D in passing through the pile as thus arranged cuts the sheets in such man nor that when removed from the table their edges are all equal and the sheets of like diameter throughout.

In Fig. 5 a modification of the flexible support for the edges of the sheets is shown. The upper face of the bed is rabbeted horizontally and a horizontally-arranged plate or projection 1", of spring metal, is secured in said rabbet with its surface flush with the face of said bed, said plate extending a determined distance beyond the edge of the bed, as shown. This form is of practically the same efiect in use as the spring-pushed bar H, but does not permit of such an acute bend of the thickened portion of the sheets, for which reason I prefer to employ said bar.

Having thus explained my invention, what I claim is- 1. In a paper-cutting machine, a bed provided with a depressible projection atits cutting-edge, substantially as and for the purpose set forth.

2. In a paper-cutting machine, a bed, in combination with a spring-tensioned bar secured at an edge thereof between said bed and the cutter-knife and having a face normally flush with the face of said bed, substantially as described 3. In a paper-cutting machine, a springpnshed bar angular in cross section and hinged by an edge to an edge of the paperbed of said machine, a face of said bar being normally flush with the face of said bed, substantially as and for thepurpose set forth.

4. The bed B, in combination with the bar 11, hinged thereto, and the spring f, interposed between said bed and bar, substantially as described.

ROBERT D. CRAWFORD.

Witnesses:

0. M. SHAW, K. DURFEE. 

